Top seal for floating tank roof side wall shoes



'July 25, 1944. J. H. WIGGINS TOP SEAL FOR FLOATING TANK ROOF SIDE WALL SHOES Filed March 2'7, 1943 FIGZ.

J [fizz-12mm Q OHN IG INS MMM ATTORNEY Patented July 25,1944

OFFICE TOP SEAL FOB FLOATING TANK ROOF SIDE WALL SHOES John H. Wiggins, Chicago, Ill.

Application March 27, 1943, Serial No. 480,868

5 Claims.

This invention relates to floating tank roof seals of the type that comprise an annular shoe, or equivalent part, carried by the roof and arranged in sliding engagement with the side wall of the tank, a flexible sealing device attached to said shoe and projecting upwardly above the top edge of same, and a radially-movable means mounted on the shoe for supporting the upper end portion of said sealing device and holding said device in snug engagement with the tank side wall, at a point above the top edge of the shoe, so as to seal the space or Joint between the shoe and the tank side wall.

The main object of my present invention is to provide a side wall shoe top sealing means of the general type or kind above referred to, that is particularly adapted for use with a tank side wall made up of overlapping. plates, joined together by rivets, due to the fact that said sealing means is of such construction or design that offsets, shoulders, rivet heads, or other protuberances on the inner face of the tank side wall wi1l.not interiere with the proper functioning of the sealing device.

Another object is to provide a floating tank roof seal of the general type mentioned, in which the supporting means for the sealing device at the top edge of a side wall shoe, not only insures said device being maintained in proper sliding engagement with the tank side wall, but also eliminates the possibility of said sealing device being cut or damaged by rivet heads, or the sharp edges of overlapped metal plates from which the side wall of the tank is constructed.

Another object is to provide a radially-movable carrier for a sealing device at the top edge of a side wall shoe, that comprises means for preventing the carrier and/or the sealing device from catching on projections, or protuberances on the tank side wall during the rise and fall of the floating roof.

And still another object of my invention is to simplify the construction and reduce the cost of the means used in floating tank roof seals for preventing gases from escaping through the space between the tank side wall and the annular shoe, or other expansible and contractible structure on the roof that is arranged in sliding engagement with the tank side wall.

Figure 1 is a vertical sectional view, illustrating my present invention,

Figure 2 is a side elevational view of the parts shown in Figure 1, looking outwardly from the center of the roof towards the side wall of the tank; and

Figure 3 is a view similar to Figure 2, but on a reduced scale, showing several of the radiallymovable carriers that support the sealing device at the top edge of the side wall shoe.

In the accompanying drawing which illustrates one form of my invention, A designates a floating tank roof, B designates the side wall of the tank, inside of which the roof is arranged, C designates an annular shoe carriedby the roof and arranged in sliding engagement with the tank side wall, and D designates a flexible, gas-tight, primary seal, that is attached to the peripheral edge of the roof and to the side wall shoe C, so as to close the annular space between the roof and the side wall shoe. The shoe C preferably consists of a circumferentially flexible, annular member of considerable depth, that is arranged in parallel, or substantially parallel, relationship with the tank side wall, but so far as my present invention is concerned, the particular construction of the floating roof A, the primary seal D, and the side wall shoe C is immaterial, and any suitable means may be used to support said side wall shoe, or mount it on the roof, such, for example, as swinging hangers on the roof, from which the shoe C is suspended, or radially-movable members on the roof that sustain the weight of the side wall shoe. In Figure 1 the reference character D' designates swinging hangers of conventional construction, from which the shoe is suspended.

The side wall shoe C is provided at its upper end with a sealing device E that projects up-' wardly from the top edge of said shoe, around the entire circumference of same. Said sealing device E is preferably formed from a piece'of flexible material, such as fabric, whose lower end is attached in a gas-tight manner to the shoe C, and whose upper end is attached to a means that supports the upper end portion of-said sealing device E and presses it against the tank side wall at a point above the top edge of the shoe C. The said supporting means for the upper end portion of the sealing device E is mounted on the shoe C, and is so constructed that it is capable of moving radially, i. e., inwardly and outwardly, with respect to the tank side wall which the shoe engages. Any suitable means or instrumentality may be used to cause said supporting means to exert pressure on the sealing device E in a direction to hold said device in snug engagement with the tank side wall, at a point above the top edge of the shoe C. In the form of my invention herein illustrated, the upper end portion of the flexible sealing device E is attached to rockable or oscillating carriers F that are pivotally mounted on the inner side of the shoe C in such a way as to move radially with relation to said shoe. The particular construction of the carriers F is immaterial, but I prefer to construct them in the form of relatively short units, arranged end to end, so as to extend circumferentially around the entire circumference of the shoe C, and mounted on the top edge portion of the shoe in such a way as to maintain the sealing device E in a position extending upwardly from the top edge of the side wall shoe 0, with a portion of said sealing device pressing against the inner face of the side wall of the tank. Thus, as shown in Figures 1 and 2, the body portion of each of the carriers F may consist of a substantially channel-shaped part that embraces and is securely attached to the top edge of the flexible sealing device E, said body portion being attached to two rock arms I, whose lower ends are pivotally mounted in lugs 2 on plates 3 attached by bolts 4, or in :any other suitable manner, to the side wall shoe C. The plates 3 are herein illustrated as being used to clamp or secure clamping rods 5 and I that are employed to fasten the sealing device E and the primary seal D to the sidewall shoe C. Each of the carriers F has associated with same a spring arm 6 that is mounted on the inner side of the shoe C, and arranged so as to force the carrier outwardly,

thereby causing the sealing device E to be held pressed tightly against the tank side wall.

In order that the secondary seal E at the top edge of the side wall shoe will function properly when it is used with a tank side wall having protuberances, projections, or oflsets on the inner face of same. as, for example, a tank side wall made up of overlapping plates 2: joined together by rivets y, I have provided means for causing the sealing device E to be carried over the tank side wall during the upward movement of the roof, without danger of said sealing device or the carriers F catching on or being cut or damaged by rivet heads or the sharp edges of overlapping plates in the tank side wall. In the preferred form of my invention herein illustrated said means consists of guides F at the upper ends of the carriers F, arranged so as to bear against the inner face of the-tank side wall at points above or in advance of the point of contact between the sealing device E and the tank side wall, and constructed so that during the upward movement of the roof, said guides F will contact with the edges of offset plates in the tank side wall, and thus cause the carriers F to rock inwardly sumciently to safely guide the sealing device E over said edges. For example, when the roof rises, the guides F engage the bottom edge of the oi!- set plate a: in Figure 1, and move the carriers F and the sealing device E inwardly away from said edge. The sealing device E, which, as previously stated, is preferably made of fabric, has enough resiliency to normally remain in touching contact with the tank side wall, and as previously stated, the spring arms 8, or equivalent parts, exert suflicient outward pressure on the carriers to hold the guiding means F on same in contact with the side wall. The guides F may or may not ride over rivet heads on the tank side wall, but there is enough clearance between the hearing points of the guides F and the body portions of the carriers F to which the top edge of the sealing device E is attached, so that no portions on the carriers F will catch on or hang on the rivet heads, and the fabric from which the sealing device E is constructed will not become jammed between the body portions of the carriers F and rivet heads in the tank side wall. Nor will it be possible for the fabric from which the sealing device E is constructed to become jammed between the body portions of the carriers F and the bottom edges of the inwardly oflset plates in the tank side wall. The guides F, above referred to. are herein illustrated as being formed by portions or extensions of the rock arms I of the carriers F, that project outwardly and upwardly from the body portions of the carriers that embrace the top edge of the fabric which constitutes the sealing device E, said extensions being curved or shaped so as to form, in effect, cam-like devices on the upper end portions of the carriers F, disposed so that when they move upwardly into engagement with a projection or protuberance on the tank side wall during the rise of the roof, the sealing device E will be carried past said projection, without, however, destroying contact between the sealing device E and the tank side wall.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A floating tank roof seal, provided with a side wall shoe, a flexible sealing device attached to said shoe and projecting upwardly above the top edge of same. a radially-movable supporting means on said shoe attached to the upper end portion of said sealing device, means for causing said radially-movable supporting means to exert pressure on said sealing device in a direction to hold said device in snug engagement with the tank side wall at a point above the top edge of said shoe, and a guiding means on said supporting means disposed so as to engage the tank side wall and cause said sealing device to pass safely over offsets, projections, or protuberances on the inner face of the tank side wall during the movement of the shoe over said wall.

2. A floating tank roof seal, provided with a side wall shoe, radially-movable carriers mounted on said shoe and projecting upwardly above the top edge of same, a flexible sealing device attached to said shoe and to said carriers and adapted to be held by said carriers in snug engagement with the tank side wall at a point above the top edge of the shoe, and cam-like devices on said carriers for the purpose described, disposed so as to bear against the tank side wall at a point in advance of said sealing device during the upward travel of the shoe.

3. In a floating tank roof seal, the combination of a side wall made up of overlapping plates riveted together, a shoe carried by the floating roof and adapted to act on said side wall, a flexible sealing device attached to said shoe and extending upwardly above the top edge of same, a supporting means for the upper portion of said sealing device mounted on said shoe, so as to move radially with respect to the shoe and hold a portion of said sealing device in snug engagement with the tank side wall at a point above the top edge of the shoe, and guiding devices on said supporting means, disposed so as to engage the tank side wall and move said supporting means in a direction to cause said sealing device to pass safely over the offset edges of the plates of the side wall during the upward travel of the shoe.

4, A structure of the kind described in claim 3, that comprises means for holding the sealing device and the guiding devices on said supporting means in yielding engagement with the tank side wall.

5. In a floating tank rooi seal, the combination of a tank side wall made up of riveted plates, a shoe carried by the floating roof, and adapted to act on said' side wall, a flexible sealing device attached to said shoe and extending upwardly above the top edge of same. a spring-actuated, radially movable supporting means, mounted on said shoe and attached to the upper end portion of said sealing device so as to hold said sealing device in engagement with the tank side wall. and a guiding means on said supporting means, dieposed so that as the sealing device approaches the ofl'set edge of a wall plate during the upward travel of the shoe. said guiding means will contact the said oiiset edge and move said supporting means in a direction to p -event the sealing device from catching on or being cut by said 10 oi'fset edge. 

